Unlocking the 'Materials Genome' to Advance Aerospace Design

Last month, researchers from the University of Sydney's School of Aerospace, Mechanical, and Mechatronic Engineering discovered a microscopy method for unraveling atomic relationships within crystalline materials such as advanced steels and custom silicon.

The aerospace industry is constantly striving to improve efficiency, performance, and safety while reducing carbon emissions and maintaining sustainability. In recent years, several technological advancements have expanded the capabilities of air travel both within the Earth's atmosphere as well as outside it. This includes advanced satellite technology for communications, additive manufacturing for lightweight components, electric propulsion for reduced emissions and reduced costs, supersonic flight for faster travel, and artificial intelligence and machine learning for enhanced operational efficiency.

Aerospace focuses on advanced materials with very specific properties. Systems usually involve different kinds of materials, ranging from ceramic thermal to carbon fiber and Titanium, which are used for myriad purposes to optimize performance.

The research in this area aims to develop multifunctional materials, which means materials that have not only structural functions but can also offer other features like active cooling. To bring advanced aerospace concepts to life, materials must be more durable, lightweight, and cost-effective than ever before. 

As the aerospace industry continues to progress, let's examine the latest groundbreaking innovations that will take it even further.

Unveiling the ‘Materials Genome' to Advance Design

Last month, researchers from the University of Sydney's School of Aerospace, Mechanical, and Mechatronic Engineering discovered a microscopy method for unraveling atomic relationships within crystalline materials such as advanced steels and custom silicon.

This means that researchers can detect even minute changes in the atomic-level architecture of these materials, enhancing our understanding of the fundamental origins of their properties and behavior. This knowledge will enable the development of advanced semiconductors for electronics and lighter, stronger alloys for the aerospace sector.

For this, researchers used atom probe tomography (APT), a technique that visualizes atoms in three dimensions (3D), to unpack the complexity of short-range order (SRO). SRO is a quantitative measure of the relative tendency for a material's constituent elements to deviate from a random distribution. Understanding the local atomic environments is essential for creating innovative materials.

By quantifying the non-randomness of neighborhood relationships at the atomic scale within the crystal in detail, SRO opens up “vast possibilities for materials that are custom-designed, atom-by-atom, with specific neighborhood arrangements to achieve desired properties like strength,” said the study lead, Professor Simon Ringer, who is the Pro-Vice-Chancellor (Research Infrastructure) at the University of Sydney.

Sometimes referred to as the ‘materials genome,' SRO has been a challenge to measure and quantify. This is because atomic arrangements occur at such a small scale that you can't see them with conventional microscopy techniques.

So, the team of researchers developed a new method using APT that overcomes these challenges, making it “a significant breakthrough in materials science,” said Ringer, a materials engineer at AMME. 

The study's focus has been on high-entropy alloys (HEAs), a heavily researched area due to their potential for use in situations that require high-temperature strength, including jet engines and power plants.

Using advanced data science techniques and drawing on data from APT, the researchers observed and measured SRO. They were then able to compare how SRO changes in a high-entropy alloy of cobalt, chrome, and nickel under different heat treatments.

According to Dr Andrew Breen, a senior postdoctoral fellow:

“(The study has produced a) sensitivity analysis that bounds the precise range of circumstances whereby such measurements are valid and where they are not valid.”

By measuring and understanding SRO, this study could also help transform approaches to materials design and show just how “small changes at the atomic level architecture can lead to giant leaps in materials performance,” said Dr. Mengwei He, a postdoc research fellow in the School of Aerospace, Mechanical, and Mechatronic Engineering.

Moreover, by providing a blueprint at the microscopic level, the study enhances a researcher's capabilities to computationally simulate, model, and then predict materials behavior. It can further act as a template for future studies in which SRO controls critical material properties. 

A Revolutionary Material to Enable Hypersonic Flight

There is a lot of interest in achieving sustained flight at hypersonic speeds, but technical challenges remain. These include managing extreme heat, developing materials that can withstand stress, extreme temperatures, and oxidation without compromising performance, and creating propulsion systems that can operate efficiently at high speeds and altitudes. 

As researchers try to find solutions to these problems, scientists from Guangzhou University School of Materials Science and Engineering reported a breakthrough in hypersonic heat shields earlier this year.

In what could be a game changer for hypersonic flight, the scientists developed a new material, porous ceramic, that provides “exceptional thermal stability” and “ultrahigh compressive strength.” 

This has been achieved using a multi-scale structure design, which the scientists say has been done for the very first time. Moreover, the quick fabrication of this high-entropy ceramics opens the door to wider exploration in the sectors of aerospace, chemical engineering, and energy production and transfer.

The researchers said the ceramics were fabricated through “an ultrafast high-temperature synthesis technique